Although a technique of generating an image of multiple disparities (for example, a stereoscopic image) using lenticular lenses is widely known, it is difficult to expand a viewing zone angle which indicates a range in which an image can be normally observed. When a viewing zone angle is expanded by increasing refraction angles of beams which form an image using lenticular lenses, the aberration increases and the beams produce crosstalk between disparities. For this reason, the beams are deflected in unintended directions.